Lifting-jack.



No. 820,832. PATBNTED MAY15, 190e. 3. D. TARVER. LIFTING JACK.

APPLICATION FILED JAN.16, 1906.

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F. D. TARVER.

LIFTING JACK.

APPLIGATION FILED JAN. 1s. 1906.

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Specification of Letters Patent.

rammed may 15,1906.

Application filed January 16,1906. Serial No. 296,317.

T0 all whom it may concern:

Be it known that l, FREEMAN D. Tanvnn, a citizen of the United States, vresiding at Blanton, in the county of Lowndes and State of Georgia, have invented new and useful lmprovements in Lifting-Jacks, of which the following is a specification.

This invention relates to lifting-jacks, the object in view being to provide a simple, effective, and convenient lifting-jack for the usual purposes embodying novel means whereby the lifting-bar of the device may be released from the holding pawls or detents preparatory to lowering the lifter-bar and the load imposed thereon.

With the above general object in view the invention consists in the novel construction, combination, and arrangement of parts hereinafter fully described, illustrated, and claimed.

In the accompanying drawings, Figure 1 is a side elevation of the lifting-jack. embodying the present invention. Fig. 2 is an edge view of the same. Fig. 3 is a vertical transverse section taken to one side of the center of the stand, showing the arrangement of liftingdogs and sustaining-pawls. Fig. 4 is a verti- .cal section through the lifting-jack, showing the dogs and pawls in elevation and the manner in which the same engage the lifting-bar. Fig. 5 is a top plan view of the lifting-j ack, and Fig. Gis a horizontal cross-section taken in line with the shafts of the sustaining pawls or detents.

The lifting-jack contemplated in this invention comprises a suitable stand, in which 1 designates the main body portion thereof, and 2 the downwardly-diverging legs, which may be provided with suitable feet 3. The body of the stand is provided with a central vertical opening 41, in which is mounted a vertically movable and sliding lifting-bar 5, provided at opposite sides with notches or teeth 6, adapted to be engaged by oppositely-arranged lifting-dogs 7, which operate througl'i slots 8 formed in the stand. The dogs 7 may be of any suitable length and are provided at their lower ends with teeth Q, adapted to engage the teeth 6 of the lifting-bar 5, as clearly shown in Fig. 1. At their upper ends the dogs 7 are pivotally connected at 10 to a twoarmed operating-lever 11, the arms of which project on opposite sides of the stand. The central portion of the lever 11 is slotted, as shown at 12, to receive the upper ends of the as shown in Figs. 5 and 6. `the opposite end of one of said shafts 15 is a dogs 7 and also to straddle the head 13 of the stand to which the lever is pivotally connected at 141-..

Extending transversely through the upper portion of the stand are parallel shafts15, upon which are mounted fast two sustaining pawls or detents 16, adapted to be moved into and out of engagementwith the teeth 6 of the lifting-bar 5 and being normally held in engagement with said lifting-bar by means of a spring 17, which connects the shafts 15 l where they project on one side of the stand, Connected fast to pawl-release hand-lever 18, while connected to the corresponding end of the other shaft 15 is a supplemental pawl release lever 19. These levers are provided at their adjacent ends and between the shafts 15 with interlocking hooks 20, the engagement between the'hooks being such that when the hand-lever 18 is vibrated corresponding movement is imparted to the lever 19, thereby causing both of the shafts 15 to be simultaneously turned to throw the sustaining pawls or detents 16 out of engagement with the teeth of the lifting-bar. This allows the lifting-bar to move downward and said lifting-bar may be gradually lowered by operating the lever 11 and properly manipulating the dogs 7. The dogs 7 are held in engagement with the lifting-bar by means of springs 21, located in the slots 8 and bearing inward against said dogs, as shown in Fig. 4. lf desired, the lifting-bar may be equipped with a sling 22 in the form of a chain or cable connected to the lower end thereof and adapted to lift objects from the ground or extract stumps and the like.

I claim-- 1. A lifting-jack comprising a stand, a lifting-bar movable vertically therein, an operating-lever, lifting-dogs connected with said lever and engaging the lifting-bar, sustaining-pawls also engaging the lifting-bar, parallel shafts on which the pawls are iixedly mounted journaled. in the stand, a spring connecting said shafts and operating to hold the pawls in engagement with the lifting-bar, and

levers fixedly mounted on said shafts and co- IIO ating-lever, lifting-dogs connected with said I locking hooks, substantially as' anrl for the lever and engaging the lifting-bar, parallel purpose described. 1o shafts journaled vin the stand, sustaning- I In testimony whereof I aEX my signature paWls Carried by said shafts and engaging the in presence of two Witnesses.

A' liftngebar, a' paWl-release hand-leverrnount- FREEMAN D. TARVER.

ed on one of said shafts, and a colnplernental Witnesses: pawl release lever mounted on the other GERTRUDE GAKMAN,

shaft, said levers being provided With nter- C. L. SMITH. 

